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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/iio/adc/adi,ad4000.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Analog Devices AD4000 and similar Analog to Digital Converters
maintainers:
- Marcelo Schmitt <marcelo.schmitt@analog.com>
description: |
Analog Devices AD4000 family of Analog to Digital Converters with SPI support.
Specifications can be found at:
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4000-4004-4008.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4001-4005.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4002-4006-4010.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4003-4007-4011.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/ad4020-4021-4022.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4001.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4003.pdf
$ref: /schemas/spi/spi-peripheral-props.yaml#
properties:
compatible:
oneOf:
- const: adi,ad4000
- items:
- enum:
- adi,ad4004
- adi,ad4008
- const: adi,ad4000
- const: adi,ad4001
- items:
- enum:
- adi,ad4005
- const: adi,ad4001
- const: adi,ad4002
- items:
- enum:
- adi,ad4006
- adi,ad4010
- const: adi,ad4002
- const: adi,ad4003
- items:
- enum:
- adi,ad4007
- adi,ad4011
- const: adi,ad4003
- const: adi,ad4020
- items:
- enum:
- adi,ad4021
- adi,ad4022
- const: adi,ad4020
- const: adi,adaq4001
- const: adi,adaq4003
reg:
maxItems: 1
spi-max-frequency:
maximum: 102040816 # for VIO > 2.7 V, 81300813 for VIO > 1.7 V
adi,sdi-pin:
$ref: /schemas/types.yaml#/definitions/string
enum: [ high, low, cs, sdi ]
default: sdi
description:
Describes how the ADC SDI pin is wired. A value of "sdi" indicates that
the ADC SDI is connected to host SDO. "high" indicates that the ADC SDI
pin is hard-wired to logic high (VIO). "low" indicates that it is
hard-wired low (GND). "cs" indicates that the ADC SDI pin is connected to
the host CS line.
'#daisy-chained-devices': true
vdd-supply:
description: A 1.8V supply that powers the chip (VDD).
vio-supply:
description:
A 1.8V to 5.5V supply for the digital inputs and outputs (VIO).
ref-supply:
description:
A 2.5 to 5V supply for the external reference voltage (REF).
cnv-gpios:
description:
When provided, this property indicates the GPIO that is connected to the
CNV pin.
maxItems: 1
adi,high-z-input:
type: boolean
description:
High-Z mode allows the amplifier and RC filter in front of the ADC to be
chosen based on the signal bandwidth of interest, rather than the settling
requirements of the switched capacitor SAR ADC inputs.
adi,gain-milli:
description: |
The hardware gain applied to the ADC input (in milli units).
The gain provided by the ADC input scaler is defined by the hardware
connections between chip pins OUT+, R1K-, R1K1-, R1K+, R1K1+, and OUT-.
If not present, default to 1000 (no actual gain applied).
$ref: /schemas/types.yaml#/definitions/uint16
enum: [454, 909, 1000, 1900]
default: 1000
interrupts:
description:
The SDO pin can also function as a busy indicator. This node should be
connected to an interrupt that is triggered when the SDO line goes low
while the SDI line is high and the CNV line is low ("3-wire" mode) or the
SDI line is low and the CNV line is high ("4-wire" mode); or when the SDO
line goes high while the SDI and CNV lines are high (chain mode),
maxItems: 1
required:
- compatible
- reg
- vdd-supply
- vio-supply
- ref-supply
allOf:
# The configuration register can only be accessed if SDI is connected to MOSI
- if:
required:
- adi,sdi-pin
then:
properties:
adi,high-z-input: false
# chain mode has lower SCLK max rate
- if:
required:
- '#daisy-chained-devices'
then:
properties:
spi-max-frequency:
maximum: 50000000 # for VIO > 2.7 V, 40000000 for VIO > 1.7 V
# Gain property only applies to ADAQ devices
- if:
properties:
compatible:
not:
contains:
enum:
- adi,adaq4001
- adi,adaq4003
then:
properties:
adi,gain-milli: false
unevaluatedProperties: false
examples:
- |
#include <dt-bindings/gpio/gpio.h>
spi {
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "adi,ad4020";
reg = <0>;
spi-max-frequency = <71000000>;
vdd-supply = <&supply_1_8V>;
vio-supply = <&supply_1_8V>;
ref-supply = <&supply_5V>;
adi,sdi-pin = "cs";
cnv-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH>;
};
};
- |
spi {
#address-cells = <1>;
#size-cells = <0>;
adc@0 {
compatible = "adi,adaq4003";
reg = <0>;
spi-max-frequency = <80000000>;
vdd-supply = <&supply_1_8V>;
vio-supply = <&supply_1_8V>;
ref-supply = <&supply_5V>;
adi,high-z-input;
adi,gain-milli = /bits/ 16 <454>;
};
};
|
